Question 1

What is the difference between distance and displacement in this straight-road lab?

Accepted Answer

Distance is the total length travelled, while displacement is the change in position directed from the initial point to the final point. In this lab the car always moves in the +x direction without reversing, so their numerical magnitudes are equal, although they are still different physical concepts.

Question 2

Why are the positions at 0, 1, 2 and 3 seconds equal to 0, 1, 4 and 9 metres?

Accepted Answer

The frozen default run uses initial velocity u = 0 and constant acceleration a = 2 m/s². Substituting into s = ut + 1/2 at² gives 0, 1, 4 and 9 m at the four selected times.

Question 3

What does the fixed yellow speed scale show?

Accepted Answer

Each yellow column represents the speed reached at a complete one-second time step. The scale remains fixed from 0 to 12 m/s, so equal increases in velocity appear as equal height increments. In the default run the speeds are 0, 2, 4 and 6 m/s.

Question 4

How do the velocity-time and position-time graphs differ?

Accepted Answer

The velocity-time graph is a straight line because v = u + at. Its vertical intercept is u and its slope is acceleration. The position-time graph is a parabola for non-zero constant acceleration because x = ut + 1/2 at².

Question 5

Can an object have zero velocity and non-zero acceleration?

Accepted Answer

Yes. At the starting instant the object has u = 0, but the applied acceleration can immediately begin increasing its velocity. Zero velocity at one instant does not imply zero acceleration.

Displacement & Uniform Acceleration on a 3D Track

About this lab

Practice